The present invention relates to plumbing valves. More particularly it relates to raised surface structures on control disks which facilitate the operation of such valves.
One form of plumbing valve operates to control flow there through by rotation of a valve control handle. The handle drives a moveable element over a stationary apertured disk. when the aperture aligns with a designated aperture or other path through or by the moveable element, flow is permitted. This type of valve is often referred to as being of the non-rising type, as there is typically no axial movement of the moveable element.
It is desirable in connection with plumbing valves to permit numerous operations, over numerous years, in a reliable fashion. This is made difficult to achieved because of the tendency of some contact parts in non-rise valves to wear, an the tendency of some parts to bind in the presence of grit or other contaminants in the water.
Generally favorable wear and operation characteristics are provided by ceramic disks. Such disks are often used in volume control valves where a single type of water is controlled. They are also used in mixing valves where volume and the mix of hot and cold water are controlled by a single valve. Further, they are found in water distribution valves where one or more inputs are directed between multiple outlets (e.g. a bath spout versus a shower). See e.g. U.S. Pat. Nos. 4,651,770, 5,398,717 and 5,823,510.
However, when the facing surfaces of the stationary and moveable ceramic disks are in complete contact across the disks (except for the apertured area). This results in the need for greater force to rotate the valve. Further, such forces can increase premature wear.
There have therefore been some efforts to reduce the area of the ceramic disks that are in contact with each other. For example, FIG. 1 depicts a prior art stationary ceramic disk 10 which has wheel, hub and spoke-shaped raised contact areas that are quite small relative to the overall top view area of that disk. While such a design reduces the frictional resistance between the two disks, all the contact force is focused along those limited contact areas. Over time this can still lead to premature wear.
Hence, a need exists for further improved disk structures for use with valves of this type.